Phase two mode can override the shunt trip function.

Phase two mode can override the shunt trip function.

• A. True
• B. False
• C. Not applicable
• D. It depends on the elevator

Answer: (B)

Phase two mode does not override the shunt trip function. A shunt trip is a safety device wired to immediately disconnect power to the elevator controller in an emergency. Its purpose is to override any normal or maintenance operating state to ensure the car cannot run when danger is present. Because safety interlocks must take precedence over operating modes, the shunt trip will trip and hold in a de-energized state regardless of whether the system is in phase two mode or any other mode. In short, safety functions are designed to override regular control to protect people and equipment, so the statement is not true.

Phase two mode does not override the shunt trip function. A shunt trip is a safety device wired to immediately disconnect power to the elevator controller in an emergency. Its purpose is to override any normal or maintenance operating state to ensure the car cannot run when danger is present. Because safety interlocks must take precedence over operating modes, the shunt trip will trip and hold in a de-energized state regardless of whether the system is in phase two mode or any other mode. In short, safety functions are designed to override regular control to protect people and equipment, so the statement is not true.